Carbureter



P. P. GILLES.

CARBURETER.

APPLICATION FILED SEPT. I7, 1918.

1,330,797. Patented Feb. 17; 1920..

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P.P. GILLES.

CARBURETER. mwucmfpu mu SEPT. 7, 191s.

Patented Feb. 17,1920.

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V UNITED STATES PATENT UFFTC.

PIERRE P. GILLES, OF SPRINGFIELD, MASSACHUSETTS.

CARBUR'ETER.

To all whom it may concern Be it known that I, PIERRE P. GILLES, born in Switzerland of German parentage, now believing myself to be a citizen of the Swiss Confederation, and having formally declared my intention of becoming a citizen of the United States of America, in conformance with the United States immigration laws, and now residing at Springfield, in the county of Hampden and State of Massachusetts, United States of America, have invented certain new and useful Improvements in Carbureters, of which the following is a specification.

This invention relates to vacuum feed carburetors and more particularly toimprovements in vacuum feed carbureters of the type disclosed in my prior Patent No. 1,269,177, granted June 11,1918.

Carbureters, of the type with which this invention is concerned, involve the joining together of the usual carbureter and the iusual vacuum feed apparatus. The two units, heretofore used separately, are, ac cording to my prior patent, combined into a unitary structure, which involves merely the usual air-intake pipe, a substantially airtight fuel chamber adapted to be directly connected to the low level fuel supply tank, and fuel conducting passages connecting the suction pipe and chamber and constituting the sole means of creating a vacuum in the fuel chamber. The construction is characterized by the entire absence of an independent means of creating a vacuum in the fuel chamber and accordingly the creation of a vacuum therein is wholly dependent on the fuel conducting passages.

In ordinary carbureters, such as may be used either with or without the known types of vacuum fuel feeding devices, it is very desirable to provide a plurality of fuel nozzles to secure the desired grade of fuel mixture under various conditions of engine operation. Thus, a main suction controlled nozzle is provided and commonly a second nozzle, called a compensating nozzle which is fed with fuel at substantially a uniform rate per unit of time, is combined with the main nozzle. Generally also there is provided a slow speed nozzle, so called because it functions chiefly on low engine speeds to provide a comparatively rich mixture at such speeds. The slovy speed nozzle generally is arranged to deliver into the suction pipe adjacent the throttle while the main Specification of Letters Patent.

Patented. Feb. 17, 1920.

Application filed September 17, 1918. Serial No. 254,468.

and compensating nozzles deliver into the suction pipe at a point between the air-intake end thereof and the throttle, which point is necessarily one of less degree of vacuum than obtains adjacent the throttle.

The present invention is mainly concerned with, and has for its broad object, the provision of means which will permit the use of the desirable arrangement of main, compensating and slow speed nozzles in a vacuum feed carbureter of the type wherein the fuel nozzles or passages constitute the sole means of creating a vacuum in the fuel chamber and thus of causing fuel to flow directly thereto from the low level supply tank.

To this end the invention embodies certain features of novelty as will more particularly appear in the following description and as will be particularly pointed out in the appended claims.

The invention is an embodiment at present preferred, is shown for illustrative purposes in the accompanying drawings, in which:

Figure 1 is a top plan view of a carbureter embodying the invention;

Fig. 2 is a sectional elevational view thereof taken on the line 2-2 of Fig. 1;

Fig. 3 is a sectional plan view taken on the line 33 of Fig. 2;

r Fig. 4 is a fragmentary sectional elevational view taken on the line H of Fig. 1;

Fig. 5 is a cross-sectional view taken on the line 55 of Fig. 1; and

Fig. 6 is a sectional plan view taken on the line 66 of Fig. 5.

Referring to these drawings: the carbu reter casing A is suitably formed to provide a main air-intake passage 10 and a fuel chamber 11, which is disposed on one side of the passage 10. The chamber 11 is closed at its upper end by a cover A in such a manner that the chamber, except for certain passages which communicate therewith in a manner to be described, is air-tight or substantially so.

The air-intake pipe 10 is suitably flanged at one end, as indicated in Fig. 3, to permit its attachment to the intake manifold of an internal combustion engine. Near the other, and air-intake, end of pipe 10 is the usual venturi 12 and the high speed andcompensating nozzles are adapted to deliver into pipe 10 adjacent the restricted part of venturi 12. Between the latter and the engine or suction end of pipe 10 is a throttle valve 13 which is operable by a lever 14 (Fig. 1) to vary the effective opening of the pipe in the usual manner. The slow speed nozzle is adapted to deliver into pipe 10 at a point 5 closely adjacent the throttle valve 13, as

will later appear.

The fuel chamber 11 is provided with a fuel connection 15, which is mounted on cover A, as shown in Fig. 2, and is adapted to be directly connected to a low level fuel supply tank. There are no passages communicating between the fuel chamber 11 and the intake pipe 10 except those through which fuel is supplied, as the high speed,

15 slow speed and compensating nozzles to be described. The creation of a vacuum, or partial vacuum, in chamber 11 is thus effected solely by the suction produced in the several fuel nozzles in a manner closely analogous to that disclosed in my prior patent above mentioned.

The high speed and compensating nozzles are both contained within a sleeve 16 (Figs. 3, 5,'and 6) which sleeve is suitably fixed in casing A (Fig. 5) and extends from the base thereof vertically upwardly into the intake pipe 10. Suitably fixed in the base of sleeve 16, and closin the lower end thereof, is a tube 17 whic extends upwardly and terminates a short distance below the upper end of the sleeve. The upper end of tube 17 is provided with a flange 18 of square cross-section (Fig. 6) whereby the upper end of the tube is held concentrically in sleeve 16 by the engagement of the corners of flange 18 with the interior of the sleeve. Intermediate the flange 18 and base of tube 17, the latter is necked down to provide anannular passage 19 between it and sleeve 16, which passage constitutes the compensating nozzle of the carbureter and communicates with the intake pipe 10 by way of the segmental spaces 20 (Figs. 3 and 6) between the flat sides of flange 18 and the interior wall of sleeve 16. The tube 17 has an axial passage 21 which opens into the sleeve 16 above flange 18 and thus into the intake pipe 10. The passage 21 constitutes the high speed nozzle of the carbureter and is regulable by a needle valve 22, which is threaded into the lower end of tube 17 and closes the lower end of passage 21.

Fuel from chamber 11 is supplied to the high speed nozzle by means of a passage 23 (Fig. 3) which extends from the lower portion of chamber 11 to an annular groove 24 (Fig. 5) formed in casing A and encompassing the described sleeve 16 adjacent its lower end. The tube 17 closely fits within sleeve 16 at this point and there are provided registering passages 25 in each, by means of which communication is afforded between groove 24 and passage 21.

Above the annular groove 24 is a second similar groove 26 and an opening 27 in sleeve 16 opens from the passage 19 into this groove, as clearly shown in Fig. 5. A horizontal passage 28, formed in the bottom wall of chamber 11, delivers into groove 26 and, intermediate the ends of passage 28, there is a short vertical passage 29 which coinmunicates between chamber 11 and passage 28. Passage 29 is regulable by a needle valve 30, which is adjustably mounted in cover A and depends through chamber 11 into co6perative engagement with the inlet end of passage 29. Thus, fuel may be supplied from chamber 11 through a restricted opening into the compensating nozzle.

The passage 28 is preferably connected to 30 the atmosphere. Referring to Fig. 5, the passage 28 communicates with the lower end of a vertical passage 31 formed in casing A, and a vertical passage 32 in cover A registers with the upper end of passage 31. 5 The upper end of passage 32 communicates with one end of a horizontal passage 33, formed in cover A as shown in Fig. 4. The other end of passage 33 communicates with the upper end of a short vertical passage 34 in cover A and the lower end of passage 34 opens into a cylindrical chamber 35. Chamber 35, as best shown in Fig. 3, is per manently closed at one end and its other end may be closed by a ball valve 36, which is yieldably urged outwardly by a spring 37 for this purpose. Slidably mounted in the wall of pipe 10, with its axis alined with that of chamber 35, is a plunger 38 which is movable away from ball 36 by a spring 39. Plunger 38 has one end extending into pipe 10 and such end is adapted to be engaged and moved by a cam 40 formed on the described throttle valve 13, whereby when the latter is turned plunger 38 may be moved to engage and move ball 36 and thus permit atmospheric communication with passage 28. The cam 40 is constructed to gradually open ball valve 36 as the pipe 10 is gradually opened by the throttle valve 13. However, when the latter is closed or only slightly open, as in slow speed running, the plunger 38 is completely retracted, as shown, so that ball valve 36 may be held in closed position, as shown.

The slow speed nozzle is best shown in Fig. 2. It includes a tube 41 which is threaded into cover A and depends a substantial distance into chamber 11. Tube 41 has an axial fuel passage 42 which communicates with chamber 11 through a restricted opening 43 at the base of the tube. The tube 41 has a conical upper end 44, which is adapted to cotiperate with the recessed lower end of a stem 45 which is threaded into cover A from above and is disposed in axial alinement with tube 41. The stem 45, except for its threaded portion and a flanged portion 46 intermediate its ends, is of reduced diameter so that upper and lower annular passages 47 and .48 are formed between it and the cover A. The flanged portion 46 partitions such passages and prevents communication therebetween. Stem 45 has an axial passage 49 therein, which communicates at its lower end with passage 42 and may also communicate with the annular passage 48 when stem 45 is so positioned that its recessed lower end is spaced from the conical end 44 of tube 41. The upper end of passage 49 communicates by means of a diametrically disposed hole 50 in stem 45 with the upper annular passage 47. The lower annular passage 48 communicates ,with the atmosphere by way of an opening 51. The upper annular passage 47 communicates with one end of a horizontal passage 52 formed in cover A and the other end of passage 52 communicates with the upper end of a vertical passage 53' in cover A. The lower end of passage 53 registers with a vertical passage 54 in casing A and the latter passage communicates with one end of a horizontal passage 55. The latter, as shown in Fig. 3, delivers into the intake pipe 10 and opens into the pipe at such a position as tobe closed by the throttle 13 when the latter is in closed position.

The slow speed nozzle normally has but a restricted communication with chamber 11. The small opening 43 allows only a relatively small amount of fuel to pass and furthermore the amount of fuel withdrawn from chamber 11 through the slow speed nozzle may be still further decreased by varying the degree of suction effective upon tube 41 for this purpose. The suction may be regulated in any desired manner, as for example by the admission of air in restricted and regulable quantities between the mating ends of tube 41 and stem 45. Although normally there is merely a restricted communication between the slow speed nozzle and chamber 11, it is desirable at times to permit a greater degree of communication, since the suction through the slow speed nozzle is relied upon, as with the main and compensating nozzles, to draw fuel into chamber 11. Therefore, a radial hole 56 is provided in tube 41 near its upper end to permit communication between passage 42 and chamber 11. A valve 57, carried by a pivoted bell crank lever 58, which in turn is operable by the rise and fall of a float 59 in chamber 11, normally closes the opening 56, but, when fuel is flowing into chamber 11 at an insuflicient rate to maintain the desired level therein, the valve 57 is opened by the falling of the float to permit the slow speednozzle to draw increased quantities of fuel into chamber 11.

Referring now to Fig. 5, means are provided to prevent communication between the intake pipe '10 and both the high speed and Fig. 6, to permit the passage of fuel from compensating nozzles at times of relatively low suction. Such means consists of a valve 60, in the nature of a check valve, which prevents any fluid from entering the delivery end of the high speed and compensatin nozzles and yet permits the delivery of fuel therefrom when the suction in pipe 10 becomes sufficient to lift the valve. As shown in Fig. 5, the valve 60 is a frusto-conical member, which is adapted to seat in the up per end of the described sleeve 16, and has a stem 61 which is slidable in the high speed nozzle passage 21. Stem 61 is of substantially triangular cross-section, as shown in the high speed nozzle and still afford a guiding engagement with the interior wall of tube 17. A screw 62 adjustably threaded into the intake pipe 10 in axial alinement with sleeve 16, depends toward the valve 60 and is arranged to limit the upward movement of the latter.

The operation of the carburetor will now be described. The chamber 11 may be originally filled with fuel in any suitable manner. For example, if the throttle 13 is opened just sufficiently to uncover passage 55 and the engine, to which the carbureter is connected, is turned over, a strong suction will be applied to chamber 11 through openings 43 and 56, the latter being available for this purpose since the float 59 is in its lower position. The stem 45 may be turned down to entirely close OK the admission of air to the slow speed fuel passage, if desired, to aid in the rapid creation of a vacuum in chamber 11. The valve 36 will remain in its closed position, as illustrated, until the throttle valve 13 is turned beyond the position just described, and obviously check valve 60 will be seated to close 03 the high speed and compensating nozzle. Thus, all connections to the chamber 11 are closed except the fuel inlet connection and the slow speed fuel passage. Consequently, 110 fuel will be drawn from the low level tank to fill such chamber.

Assuming then that chamber 11 is filled with fuel to the desired level and assuming also that the engine is running at low speed, 115 the throttle 13 will be nearly in closed position and only open sufficiently to allow fuel to flow from passage 55 into the intake pipe 10. With the throttle 13 thus positioned, it is obvious that a much higher degree of 120 vacuum obtains in pipe 10 at a point ad jacent the passage 55 than at a point adjacent the main and compensating nozzles. Consequently, it is essential to close off such nozzles for otherwise air would be drawn 125 therethrough and into chamber 11 as fast as fuel is drawn out through the passage 55. Thus, fuel would be prevented from being drawn by suction into the chamber 11 and the level of fuel therein would drop, where- 130 upon valve 57 would open and allow air rather than fuel to then pass into the intake pipe through the slow speed passage. The valve 60 prevents inflow of fluid of any sort into the chamber 11 and the valve 36, which is also in closed position on slow speed operation, likewise prevents the admission of air to the compensating nozzle and thus a possible interference with the operation of the carbureter on slow engine speeds.

On higher engine speeds, the throttle 13 is opened increasingly and obviously as the throttle is opened, the conditions formerly obtaining in pipe 10 of marked differences in pressure adjacent the slow speed and high speed passages no longer exist. There is then a comparatively large volume of air which travels at high velocity through the venturi 12 and acts to lift valve 60, whereby fuel is drawn from the high speed and compensating nozzles. As soon as the throttle 13 is opened beyond its normal position for slow speed operation, the ball valve 36 is opened and is also opened increasingly with the throttle. The admission of air to the passage 28 (Fig. 5) changes the character of the annular nozzle 19, which is no longer controlled purely by suction. That is, fuel will now pass into passage 28 through the restricted opening 29 at substantially a uniform rate in a manner similar to that in the ordinary carbureter which employs the coin pensating nozzle. The main and compensating nozzles function in compensating relation and cooperate in the usual known way to insure a substantially uniform mixture of fuel and air over a wide range of engine speeds.

The important feature of the present invention is the provision of means to permit the admission of air to the compensating nozzle under normal conditions of operation and to prevent such admission when it would detrimentally affect the operation of the carbureter. This feature is peculiar to the carbureter construction wherein the fuel is drawn by the nozzles from a chamber under less than atmospheric pressure. In the ordinary carbureter using the compensating nozzle fuel is taken from an ordinary float chamber which is under atmospheric pressure although in many instances the fuel is supplied to such chamber from a low pressure fuel supply. Here, however, the one chamber is used in place of both the usual fuel supply chamber and the carbureter floatchamber and, on this account, the provision of the automatic aircontrol for the compensating nozzle becomes essential and important to successful operation.

The supply of fuel is maintained in chamber 11 solely by the suction produced through the several fuel conducting passages and in a manner more particularly set forth in my above mentioned prior patent. It should be pointed out, however, that should the fuel fall below a predetermined level, the slow speed fuel passage becomes available to effect rapid replenishment of chamber 11. Thus, the slow speed passage has normally only restricted communication with chamber 11 through openings 4L3, but, whenever the level of fuel in the chamber becomes low, additional communication between said passage and the chamber is provided by the opening of the float controlled valve 57.

It should also be noted that the tube 4-1 is so arranged that it becomes filled with fuel for a substantial distance whenever the engine is not in operation. Thus. the

equivalent of the deep fuel well usually provided in connection with slow speed nozzles is'aiforded, whereby on starting the engine a rich fuel charge is available. Subsequently, however, and during normal operation, fuel can pass only at a very slow rate by reason of the purposely restricted inlet 43.

A further important feature of the invention consists in the means, whereby the main and compensating nozzles may be located at a distance from the slow speed nozzle, and still allow of the peculiar fuel feed solely by the nozzles themselves. Such disposition of the nozzles in the intake pipe is usual and desirable, but not practical heretofore in a vacuum feed carbureter, wherein the only means of exhausting the fuel supply chamber consists of the nozzles themselves. The check valve arrangement. however, permits this desirable disposition of the nozzles in a vacuum feed carbureter of the type just described by preventing flow through the main and compensating nozzles into the fuel supply chamber whenever a marked difference in pressure exists in the intake pipe between such nozzles and the slow speed fuel passage.

The invention has been disclosed, in an embodiment at present preferred, for purposes of illustration, but the scope of the invention is defined by the appended claims rather than by the foregoing description.

hat I claim is- 1. In a carbureter, an air-intake pipe adapted for connection at one end to suction means, a substantially air-tight fuel chamber adapted for connection to a low level fuel supply tank, fuel conducting passages connecting said intake pipe and chamber and constituting the sole means of creating a vacuum in said chamber, one of said passages opening into said pipe at a point between a second passage and the other end of said pipe, and a valve associated with the firstnamed passage to permit flow therefrom into said pipe and prevent flow in a reverse direction.

2. In a carbureter, an air-intake pipe adapted for connection atone end to suetion means, a substantially air-tight fuel chamber adapted for connection to a low level fuel supply tank, a fuel conducting passage connecting said pipe and chamber and normally communicating with the latter near the base thereof, means operable when the fuel in said chamber falls below a predetermined level to permit communication between said passage and the upper part of said chamber, a second fuel conducting passage connecting said chamber and pipe and opening into the latter at a point between the first-named passage and the other end of said pipe, and a valve associated with the second passage to permit flow therefrom into said pipe and prevent flow in a reverse direction.

3. In a carbureter, an air-intake pipe adapted for connection at one end to suction means, a substantially airtight fuel chamber adapted for connection to a low level fuel-supply tank, fuel conducting passages connecting said pipe and chamber and constitutinga means for creating a vacuum in the chamber to draw fuel therein from the low level tank, one of said passages communicating with the chamber through a restricted opening, a passage connecting the last-named fuel passage to the atmosphere, and an inwardly opening spring pressed valve to close the inlet end of the atmospheric passage until a predetermined degree of suction is established therein.

4. In a carbureter, an air-intake pipe adapted for connection at one end to suction means, a substantially air-tight fuel chamber adapted for connection to a low level fuel-supply tank, fuel conducting passages connecting said pipe and chamber and constituting a means for creating a vacuum in the chamber to draw fuel therein from the low level tank, one of said passages communicating with the chamber through a restricted opening, a passage connecting the last-named fuel passage to the atmosphere, and means to close the inlet end of the atmospheric passage until a predetermined degree of suction is established therein.

5. In av carbureter, an air-intake pipe adapted for connection at one end to suction means, a throttle valve in said pipe, a substantially air-tight fuel chamber adapted for connection to a low level fuel-supply tank, fuel conducting passages connecting said pipe and chamber and constituting a means for creating a vacuum in the chamber to draw fuel therein from the low level tank, one of said passages communicating with the chamber through a restricted opening, a passage connecting the last-named fuel passage to the atmosphere, and a valve to open and close the last-named end of the atmospheric passage simultaneously with the opening and closing of the throttle valve.

6. In a carbureter, an air-intake pipe adapted for connection at one end to suction means, a substantially air-tight fuel chamber adapted for connection to a low level fuel supply tank, one or more fuel conducting passages connecting said chamber to said pipe at one point intermediate its ends, another fuel conducting passage connecting said chamber to said pipe at a point between the first-named end and said point, and means associated with the first-named passage or passages to permit flow therefrom into said pipe and to prevent flow in a reverse direction.

7. I11 a carburetor, an air-intake pipe adapted for connection at one end to suction means, a substantially air-tight fuel chamber adapted for connection to a low level fuel Supply tank, two fuel conducting passages connecting said chamber to said pipe at a point intermediate its ends, one of said passages communicating with the chamber through a restricted opening, an air inlet passage intersecting the last-named fueli passage, another fuel conducting passage connecting said chamber and pipe and opening into the latter at a point between its first-named end and said point, means associated with the first-named fuel passages to permit flow therefrom into said pipe and to prevent flow in a reverse direction, and means to close the inlet end of the air passage when the last-named fuel passage only is supplying fuel to said pipe.

8. In a carbureter, an air-intake pipe adapted for connection at one end to suction means, a substantially air-tight fuel chamber adapted for connection to a low level fuel supply tank, fuel conducting passages connecting said pipe and chamber, one of said passages opening into said pipe at a point between a second passage and the other end of said pipe, and a valve associated with the first-named passage to permit flow therefrom into said pipe and prevent flow in a reverse direction.

PIERRE P. GILLES. 

